Being able to dial telephone calls the way customers have come to expect is considered important for the convergence of classic telephone service and Internet telephony, such as voice-over-Internet Protocol (“VoIP”). In classic telephone service, a party is associated with one or more personal identifiers (e.g., a telephone number) that might be used for one or more communication services such as, for example, handling telephone calls, sending or receiving text messages or email, or other services. Telephone number mapping typically involves harmonizing the telephone numbering system of the public-switched telephone network (“PSTN”) with the addressing and identification-name spaces of data networks (including public data networks such as the Internet) to allow communication with a party. Telephone numbers are typically organized according to the E.164 standard, promulgated by the International Telecommunications Union (“ITU”), while the Internet uses the Domain Name System (“DNS”) to link domain names to Internet Protocol (“IP”) addresses and/or other resource information. Telephone number mapping systems involve determining applicable network (e.g., Internet) communications servers or devices responsible for servicing a telephone number using DNS lookups.
A common facility for telephone number mapping is based on the E.164 Number Mapping standard (“ENUM”), developed by the Internet Engineering Task Force (“IETF”). The ENUM protocol uses customized DNS record-types to translate a PSTN-like telephone number into a Uniform Resource Locator (“URL”) or IP address that can be used for Internet or data communications.
Implementation of ENUM typically involves a request by an element of a telecommunications network. An ENUM request typically contains information for performing number mapping, but the ENUM request does not contain sufficient information to allow a carrier to make network routing and/or class-of-service decisions.